1. Field of the Invention
The present invention relates to a signal processing apparatus, and in particular, to a video signal processing apparatus.
2. Background of the Related Art
As shown in FIG. 1, a related art video signal processing apparatus is provided with a luminance signal processing unit 1 for controlling a picture status (brightness, contrast and the like) with regard to a luminance signal Y. The luminance signal Y is separated from a composite video signal in accordance with a video control signal VC.
The luminance signal processing unit 1 is connected between a video signal separating unit (not shown) for separating luminance signal Y from the composite video signal, which is outputted via an antenna and a tuner, and a matrix (not shown) for separating primary color signals R, G, B from the luminance signal Y. The video control signal VC serves to control a contrast and a brightness with regard to video signals.
The operation of the related art video signal processing apparatus will now be described. First, the video signal separating unit (not shown) separates luminance signal Y from the composite video signal received through the antenna and the tuner. The video control signal VC for controlling brightness and contrast of a screen picture is outputted from a microprocessor (not shown). The luminance signal processing unit 1 automatically controls and outputs to the matrix (not shown) a picture status (brightness, contrast and the like) with regard to a luminance signal Y separated from a composite video signal in accordance with video control signal VC. The controlled luminance signal is separated by the matrix (not shown) into the primary color signals R, G, B, which are then displayed on the picture screen.
The related art video signal processing apparatus has various disadvantages. When the luminance signal Y has a high frequency band, a large black/white comparison, and experiences a contrast processing in the luminance signal processing unit 1, a black/white comparison degree in the high frequency band may be relatively larger than other frequency bands. As a result, when the luminance signal Y is displayed on a picture screen, the high frequency band can cause a screen flickering phenomenon because of the relatively larger black/white comparison.